Analysis of mouse MSC from WT and hemophilia A C57Bl/6 mice. (A) FACS (fluorescence-activated cell sorter) characterization of MSCs isolated from bones of 3-week-old mice followed by 4 passages in culture. Cells were stained with antibodies shown. Markers typically associated with MSCs (ie, CD44, CD29, ScaI, CD90, and CD106) were present, whereas hematopoietic markers, CD34 and CD45, or endothelial marker, CD31, were absent. (B) RT-PCR showing FVIII mRNA in LSECs and MSCs from WT mice and its absence in cells from hemophilia A mice, along with β-actin mRNA to indicate equivalent cDNA loading. (C) Colocalization of nestin and FVIII by ab61390 FVIII antibody in MSCs from WT and hemophilia mice. (D) Identification of transplanted MSCs in hemophilia mice after 7 days with staining for nestin along with FVIII by ab61390 FVIII antibody; mc = microcarriers.